This invention relates to an unloading ramp assembly, and more particularly to an unloading ramp assembly for vibratory finishing machines of the toroidal bowl variety.
One type of vibratory finishing machine which has gained relatively widespread commercial acceptance incorporates a toroidal bowl or hopper which is annular in shape and U-shaped in cross section. In the use of such a vibratory finishing machine, a suitable media and piece parts to be finished are introduced into the hopper, together with a liquid such as water and in some instances a finishing agent. Vibratory apparatus is then utilized to effect vibration of the hopper and the contents thereof, whereby the piece parts are finished. Simultaneously the contents of the hopper are caused to follow a circular path around the annular interior of the hopper.
Apparatus for effecting unloading of the toroidal bowl type of vibratory finishing machine has been provided herebefore. However, the presently available apparatus generally comprises relatively complicated parts, and is therefore expensive to manufacture and use. Another disadvantage involves the fact that presently available unloading apparatus is sometimes difficult to use, and typically involves periodic maintenance. It is therefore apparent that a need exists for a substantial improvement in the art.
The present invention comprises an unloading ramp assembly which overcomes the foregoing and other disadvantages which have long since characterized the prior art. In accordance with the broader aspects of the invention, a rod extends above and across the U-shaped cross section of the hopper of a vibratory finishing machine, and defines a generally horizontally disposed axis. A ramp is adapted for engagement with the rod, whereby the ramp is supported for pivotal movement about the axis. The ramp extends from a lower end which engages the bottom of the hopper to an upper end positioned adjacent an input platform. The input platform extends to a media separation assembly which includes an apertured plate adapted to allow the media to pass therethrough and to return to the hopper under the action of gravity while supporting the piece parts and preventing the piece parts from returning to the hopper. The apertured plate in turn extends to an output platform which directs the piece parts out of the vibratory finishing machine.
In accordance with other aspects of the invention, the insertion sequence for the ramp is initiated by engaging the upper end of the ramp with the rod across the full width of the ramp. The lower end of the ramp is then allowed to come into engagement with the moving media and piece parts in the hopper of the vibratory finishing machine. This causes the ramp to be pivoted downwardly until the lower end thereof engages the bottom of the hopper. The withdrawal sequence for the ramp is initiated by pivoting one side of the ramp out of engagement with the rod. The moving media in the hopper of the vibratory finishing machine then causes the ramp to pivot upwardly and outwardly, whereby the ramp is discharged from the hopper of the vibratory finishing machine.
The media separation assembly is preferably removable so that the unloading ramp assembly may be fitted with a media separation assembly which is configured for a particular combination of media and piece part sizes. Side walls extend upwardly adjacent the input platform, and side walls extend upwardly adjacent the apertured plate of the media separation assembly to prevent media and/or piece part spillage. A side wall may extend forwardly from the input platform around the exterior of the hopper of the vibratory finishing machine, also to prevent media and piece part spillage.
In accordance with a first embodiment of the invention, the ramp is manually positioned both to initiate the insertion sequence and to initiate the withdrawal sequence. In accordance with a second embodiment of the invention, a fluid powered cylinder is utilized to position the ramp in order to initiate the insertion sequence and to position the ramp in order to initiate the withdrawal sequence. The operation of the fluid powered cylinder may be either semiautomatic or fully automatic in nature, with fully automatic operation being characterized by actuation of the fluid powered cylinder in accordance with a predetermined time sequence.